Box-handling apparatus



.April 27, 1954 Q. E. BASHORE 2,676,697 'BOX-HANDLING APPARATUS Filed oct. 25, 1948 3 Sheets-sheet 1 /6 JP" .1. 5 '5r 5V /Ecwe April 27, 1954 Q, E. BAsHoRE 2,676,697

BOX-HANDLING` APPARATUS Filed Oct. 25, 1948 3 Sheets-Sheet 2 g 7"N, ji afm EL; l,

April 27, 1954 Q. E. BAsHoRE K 2,676,697

BOX-HANDLING APPARATUS Filed Oct. 25, 1948 3 Sheets-Sheet 3 Patented Apr. 27,V 1954 UNITED STATES vPATIEIN'I BOX-HANDLING APPARATUS Quintet E. Bashore, Gnvina,-Calii.

ApplicationOctober 25, 1948, Serial No. 56,384

.2 Claims.

1 My invention relates 'to .apparatus 'for handling such articles :as rboxes, `car-tons, trays, etc., which articles are all .designated hereinafter by the generic term boxesf and, since I.the invention vwas originally embodied .in and is particularly applicable Vtoan apparatus for nnsta'cking boxes, .I iprefer to consider :such an embodiment herein for convenience. However, `as will .be evident hereinafter, YMarions features vof .theinvention ,may be-:embodied in other apparatus without departing from the spirit thereof, and it will 'be :under- .stood,rtherefore, that EI do not .desire to be limited to the specific embodiment disclosed herein :for

'purposes .of illustration.

The present invention :embodies improvements on vthe :apparatus rdisclosed my copending zapplication Serial No. 757,522., `filed .June 2'7, `1941i, :and now Patent No. 2,590,225, .and entitled Box Handling Mechanism," reference Lto which is hereby made..

Before proceeding to :disclose -the present invention in detail, it is -convenient vto discuss one of :the possible industries in which lit is applicable with Aparticular ,advantage In .the citrus ,fin- -dustry, .for example, extensive handling of boxes containing :fruit is necessary in processing qthe .fruit fin packing houses, it frequently being necessary to stack and unstack boxes scontainng the .fruit several .times between its arrival at :the

packing house .from the `groves and its :shipment tothe-consumer. Lemons, for example, are {or- 'dinarily .picked ovh-ile partially green and must bestored for asconsiderable length of time betore .shipment .to ypermit ythem to cure. The usual practice is :to v:sort Aand Wash the lemons .upon

:arrival at the packing vhouse fand, subsequently, to .pack the lemons in :boxes :are thenplaced fin storage. After 4the lemons .have been .stored -fzor .a lsuiiicient :length of time. .they :are ithe-n .prepared for shipment.

From the foregoing, it will be apparent that .the boxes containing 'the fruit :must 7be handled several .times prior to shipment. Since, in order tto conserve space, .the boxes are frequently placed in stacks of ten or more, :it lwill be apparent that :unstacking the boxes, fe. g., fduring :removal from storage, rpresents a `serions problem, Iespecially since-lemons inV particular fmust :be handled vcarefully in order tto prevent bruising.

With the 'foregoing observations in mind, it is a general object .sof my invention .to provide an apparatus torireinoving'boxes from astack. preferably one Vat -a time, and -for transporting the boxes to asuitablebox-*receiving stat-ion.

' More specically. lit "is `an object Yto provide nnstacking apparatus -which includes means :for scontinuously elevatinga stack of boxes from .a `stack-reeeiving station, .and which includes carriage means for removing .successive boxes from :the top of .the rising stack and for transporting .the boxes'removed from the stack to the box-receiving station. Arelated object is to provide an apparatus which includes means for transporting each box from the box-receiving station .before .arrival of the next box, which .means may be 4a .suitable conveyor.

.Another object of rthe invention is -to provide an unstacking apparatus of the foregoing .general character wherein the .carriage means is driven at a. higher rate of speed than the .elevatingimeans .so thatseach box is lifted clear of the rising stack immediately after it is engaged by the .carriage means.

A further object of the invention is to provide a :carriage `means which is rotatable relative to a y,supporting vstructure .or frame, and on which axplural-ity lof pairs of box-.engaging devices are mounted, the box-engaging devices of each pair being ,adapted `to Yreceive a box therebetween and `to nonvey :it to the tbox-receiving station.

important'object of the invention is to provide -an apparatus having means for maintaining -the, Aorientation -of Y.the :box-engaging devices `constant with respect 'to the frame so as to mainztain vthe boxes l.carried thereby .in upright posi- .tions at .all :times while they are `being trans- ;por-ted Ito the .box-receiving station.

An additional object :of the invention is to provide an apparatus wherein the elevating .means and #the carriage :means operate in timed relationship in such a manner that the boxengaging idevices ;of each pair engage .each box on Opposite surfaces thereof at points substan- =tially adjacent the bottom of the box. This permits the box-engaging fdevces to engage the strongestgportion of each boxto prevent damage thereto, which is an important feature of .the invention.

`Another important object is :to provide a con- .struction wherein each pa-ir .of box-engaging .devices includes ia pair lof box-engaging Vmembers which are iadapted to engage opposite vertical :surfaces -of fa box to clamp it therebetween, such box-engaging members providing the sole means `for Agrasping the box.

Still another :important :object .of `the 4inven- .tion vis :to :provide a box-handling mechanism :of the foregoing .character i.wherein vthe .box-.engaginganembers ofeadhpair-of Iinox-engaging devices xare movable Nfrom inoperative to voperative posi invention.

when in their operative.

positions, are inclined upwardly from their re' spective axes of rotation so that the weight of a box engaged thereby tends to rotate them even closer together to increase the clamping forces applied to the box.

Another importan-t object of the present invention is to provide a construction wherein the box-engaging members are loosely connected to suitable supporting members. Such lost-motion connections betweenthe box-engaging members land the supporting members therefor permit shifting of the box-engaging members with respect to the supporting members to accommodate boxes having irregular, e. g., warped, surfaces, which is an important feature of the A further object is to provide an apparatus having cam means for moving the box-engaging members between their respective operative and inoperative positions. A related object is to provide a cam means which operates in timed relationship with the carriage means and the stack-elevating means in such a manner that the box-engaging members are moved into their operative positions at substantially the instant `that a box in the stack has been elevated to the proper position for removal from the stack. Another object in this connection is to provide a loam means which operates in timed relationship with the carriage means in such a manner that the box is released at substantially the instant that it arrives at the box-receiving station.

Preferably, the stack-elevating means 'com-x `prises a conveyor which includes one or more endless, flexible conveying members trained over wheels, and which includes one or more boxadvancing means connected to the conveying members. may be chains, belts, or the like and the wheels over which they are trained may be sprocket wheels, pulleys, or the like.

An important object is to provide an apparatus having a conveying means of the character set forth in the foregoing paragraph wherein the box-advancing means is adapted to be folded or rjackknifed into a position such that it will move :around wheels of relatively small diameter. This construction reduces the space required by the conveying means to a minimum, which is an important feature of the invention.

Another important object of the present invention is to provide a box-handling apparatus having means for rotating a box about a substantially vertical axis through an angle of substantially 90 while the box is being moved horizontally, substantially Without changing the direction of movement of the box. This construction permits the box to be rotated from a position wherein it is moving sidewise to a position wherein it is moving endwise, which is an important feature of the invention. v

Still another important object of the invention is to provideV a box-handling mechanism of the For example, the conveying members 4 foregoing general character which handles the boxes gently and with a minimum of jolting so as to substantially eliminate any possibility of `damage to the contents of the boxes.

The foregoing objects and advantages of the invention, together with various other objects and advantages thereof which will be evident hereinafter, may be attained through the employment of the exemplary embodiment illustrated in the accompanying drawings and `described in detail hereinafter. Referring to the drawings, which are intended as illustrative only:

Fig. 1 isV a vertical sectional view of a boxyhandling apparatus which embodies the invention; I

Fig. 2 is a 4front elevational view of the apparatus and is taken in the direction of the arrows intersecting the broken line 2-2 of Fig. l;

Fig. 3 is a plan view of the apparatus;

Fig. 4 is a fragmentary sectional View illustra-ting the operation of a box-advancing means which forms part of the apparatus;

Fig. 5 is an enlarged, fragmentary elevational view showing one side of a carriage member which forms part of the apparatus, Fig. 5 being taken in the direction of the arrows intersecting .the broken line 5-5 of Fig. 2;

' Fig. 6 is an enlarged, fragmentary sectional view showing the opposite side of the carriage ,member illustrated in Fig. 5;

Fig. 7 is an enlarged, fragmentary sectional view taken along the broken line l-.l of Fig. 6;

Fig. 8 is a developed View of a cam which forms part of the apparatus; and

Fig. 9 is a side elevational view of a gripping element which forms part of the apparatus.

Referring particularly to Figs. l, 2 and 3 of the drawings, I show a box-handling apparatus embodying my invention which includes a frame l0, means indicated generally by the numeral li Afor continuously elevating a sta-ck i2 of boxes 13 from a stack-receiving station ld along a `generally vertical path, carriage means indicated generally by the numeral l5 for removing successive boxes from the rising stack and for moving such boxes to a box-receiving station I6, and conveyors l1 and i8 for moving the boxes from the box-receiving station to some other station y(not shown) which may be a suitable processing station, for example. At the junction of the conveyors I and is, I provide means indicated generally by the numeral i9 for rotating each box about a substantially vertical axis through an angle of substantially each box being adapted to be moved sidewise by the conveyor il and endwise by the conveyor i8. The apparatus also includes means 2%, which may be a variable speed electric motor, for example, for driving the stackelevating means il, the carriage means l5 and the conveyor l1.

Considering the apparatus in more detail, the stack-elevating means il, which preferably lifts the stack l2 along a slightly inclined path to #prevent tipping thereof, includes a pair of endless, flexible conveying members 2e each of which is trained over Wheels 25 and 2t, the wheels 25 and 26 being fixed on shafts Z1 and 2t, respec- |tively, which are journalled in suitable bearings carried by the frame le. In the particular construction illustrated, the exible conveying inembers 24 are chains and the wheels 25 and 2t over which they are trained are sprocket wheels.

The stack-elevating means l l is driven from a shaft tl by anrendless chain 32 which trained antojo? over a sprocket 3'3 fixed on Vthe shaft 121 of the stack-elevating means and which 'is 4trained over a sprocket 34 fixed on the shaft -3l. IThe shaft 3| is driven by the motor '20 through an `endless chain 35 which is ltrained overa sprocket 36 fix-ed on the shaft 3| and which is trained over `a sprocket 37 ixed on the shaft of the motor. 'Referring to Fig. 1 of the drawings, it will be apparent that i-I" the motor 20 rotates in the clockwise direction, the chains V24 of "the stack-elevating means II will be driven in the clockwise fdirection also through the mechanism described. The elevating chains 24 carry advancing means t8 for supporting and elevating the stack I2. The advancing means 40 comprises a pair of advancing or supporting members '4I upon which the stack I2 is adapted to rest, 'the supporting members being pivotally connected to the respective chains 24 at 42. The advancing means #10 also includes a pair of toggle joints each comprising nrst and second toggle elements 43 and 44 which are pivotally interconnected at 45. The lirst toggle elements -43 are 'p'ivotally connected to the respective chains 2li at l46 and the second toggle elements '44 are pivotally connected to the respective supporting members `4I at l1H. Link elements 48 extend between the respective supporting members 4i and iirst `toggle elements 143, each link element 458 being 'pivota'lly connected to the corresponding supporting member `ll-'I Arat 9 and being pivotally :connected to the 'corresponding iirst toggle element 43 at 5D.

Referring particularly to Fig. 4 of the drawings, the foregoing construction permits the advancing means fitto be folded or jackknifed as the portions of the chains 214 lying between 'the pivot points $2 and d5 engage the sprocket wheels 25, or the sprocket wheels 2t. As shown inFig. 4, the distance between the pivot points i2 and 4S decreases as the chains '24 engage and are wrapped 1 around the sprocket wheels and the toggle joints formed by the toggle elements -43 and 1416 are broken to permit movement of the 'advancing means 4i! around the sprocket wheels. With this construction, sprocket wheels having a relatively small diameter may be employed to reduce the space requirements of the elevating 'means Ifi, which is an important Afeature of the invention. Preferably, two orjmore advancing means 4t are provided, these being spaced apart along the elevating chains 2*"4 distances vsuch that '-by the time one of the advancing means has elevated the bottom ci a stack I2 toca point above 'the top rof a succeeding stack, lthe next advancing means will be in a position to lift the succeeding stack.

Each advancing means 4-0 is adapted to pass through van open, rectangular platform 54 lon which a stack I2 lof boxes may be placed-so that it will Vbe `picked up by one of the advancing means as it passes through the platform. The

dimensions `of the stack-receiving platform 154 must, of course, be such that it will support the stack )of boxes in a position to be engaged Vby one of the advancing inea-ns v40 while lpermitting the advancing means to pass therethrough.

1 En the particular construction illustrated' in the drawings, the lapparatus is designed to receive a stack oi boxes from a hand truck, 4or the like, although it will 'be understood that xa suitable automatic conveyor system (not showni may be provided iormoving stacks; of boxesv intojposition on the v'stack-iceiving platform 5t. order to permit the Vstacks of boxes to be placed Ion lthe platform 543 'by a hand truck or asimilar device,

the apparatus is preferably located in a pit te below the level of the surrounding floor 25B. However, it will'be understood that locating the apparatus in a pit may not ybe necessary -if an automatic conveyor system is used to move the stacks of box-es into position on the stack-receiving platform 54.

will thus be apparent that the stack-elevat-l ing means Il is adapted to engage a stack ft2 lof boxes which has been placed on the stack-receivingplatiorm 54 and is adapted to move the stack continuously in a 4generally ver-tical direction toward the carriage means I5. As previously indi-- cated, the carriage means, which will now be described in detail, removes successive boxes from the top of the rising vstack and transfers them to the box-receiving station i5, from which they are movedby the conveyors I-I and VI 8.

The carriage means -I 5 comprises a pair of -carriages or vcarriage members 60 which are Lr tatabl'e on the shaft 27 of the stackelevating means II. As best shown in Figs. 5 and 6-oi the drawings, the carriages vcomprise discs having sprocket teeth 6I thereon and are, in eiect, sprocket wheels. As best shown in Figs. l, 2 and 3 of the drawings, the carriages 6G are 'rotated about the shaft 2'1 by chains '52, the latter being trained over the respective carriages and lbeing trained over sprockets 433 Xed on the shaft '3 I. y

Each lof the carriages 60 has rotatably mounted thereon a plurality of vbox-engaging devices B5, three such devices being provided -on each carriage in the particular construction illustrated although this number 'may be varied if desired. Each of the box-engaging devices B5 on one of the carriages G is paired with one of the boxengaging devices on the other carriage, vthe -devices of each pair being adapted to `receive the uppermost box in the stack I2 therebetween and being adapted to frictionally engage opposite surfaces of this box as will be discussed in more detail hereinafter. Rotation' of the carriages Sil causes the vbox-engaging devices 55 of each pair to move a box carried. thereby to the box-receiving station YI as will be discussed in more detail hereinafter, such rotation of the carriages being in the clockwise direction as viewed in Fig. l of thedrawings. The carriages 6c are driven at a speed such that the box-engaging devices 85 -move at a speed exceeding that of the rising stack I2 so 'that each pair of box-engaging devices lifts the box carried thereby clear of the remaining boxes in the stack immediately after engaging it, which is an important feature of the inven tion. Preferably, the box-engaging devices 65 move at a speed approximately twice that of the rising stack I2 toinsure that the bex carried by each pair of box-engaging devices is lifted clear of the remaining boxes in the stack. Subsc quently, each pair of box-engaging devices 55 moves the box carried thereby along a circular discharge path to vthe box-receiving station le.

The con-struction of the box-engaging devices 65 7will now be described with particular reference to Fig. 7 of the drawings wherein one of the de vices is shown in detail, the construction of the remaining devices E5 being identical -to that of the one shown in Fig. 7. Each box-engaging device B15 includes asupporting member or bracket $6 having a hub 61 which is journalled in a bearing 68 carried by the carriage @il on which the device is mounted. Axial 'withdrawal of the hub 61 from the bearing S8 toward the left, as viewed in Fig. 7 -`of the drawings, is prevented by a ring 69 pressed on'the hub t7. A box-engaging member or clamping member 12 is pivotally connected to the supporting bracket 65 by a shaft 13, the clamping member 12 comprising a pair of spaced box-engaging or gripping elements 14 which are preferably provided with corrugated surfaces 15, or the like. The gripping elements 14 are interconnected by a rod 1B to which one end of a link member 11 is pivotally connected, the link member being slidable in an opening through a fitting 18 which is rotatable on the rod 16. The opposite end of the link member 11 is pivotally connected to the supporting bracket 66. A compression spring 19 encircles the link member 11 and tends to rotate the rod 16 and the grip-ping elements it connected thereto in the counterclockwise direction, as viewed in Fig. 7 of the drawings.

The gripping elements 14 and the link member 11 form a toggle joint which is adapted to be broken by a plunger 8l to permit counterclockwise rotation of the gripping elements 14, as viewed in Fig. '7 of the drawings, the plunger 8l having a stern 82 which is slidable in a bore 83 in the hub El of the bracket 66 and which terminates in eyes 94 having slots 85 therein. The rod 1-6 connecting the gripping elements 14 extends through the slots 85 in the eyes 84, the eyes being disposed on opposite sides of the fitting 18 providing the pivotal connection between the link member 11 and the rod 16 to prevent axial movement of the link member. It will be apparent that the purpose of the elongated slots 85 is to permit vertical movement of the rod with respect to the plunger 8| as the gripping elements 14 rotate about the shaft 13.

The gripping elements 14 are loosely mounted on the pivot shaft 13 and are loosely connected to the rod 16 therebetween, as by being provided with enlarged holes 13a and 16a, Fig. 9, for the pivot shaft 13 and the rod 16, respectively. Thus, the gripping elements 14 may shift or wobble relative to each other and to the supporting bracket 66 to accommodate irregular box surfaces. Thus, if a box having a warped surface is encountered, the gripping elements 14 may shift L..

with respect to each other so that they are different distances from the supporting bracket 96 to accommodate such a warped surface. Also, because of the lost-motion connection between the gripping elements the gripping elements pivot shaft to aid boxes.

The clamping member 12 of each box-engaging device is rotatable about the axis of the pivot shaft 13 from a retracted, or inoperative position to an extended, or operative position wherein the gripping elements 'i4 thereof engage a box I3. The clamping members 12 of the lowermost boxengaging devices visible in Fig. 2 of the drawings are in their retracted, or inoperative positions, and the clamping member of the box-engaging device shown in Fig. 7 is in its extended, or operative position. As previously indicated, the gripping elements 14 and the link member 11 pivotally connected to the rod 16 between the gripping elements form a toggle joint which is adapted to be broken by the plunger 3l upon movement of this plunger toward the left, as viewed in Fig. 1 of the drawings. After the toggle joint is broken, the spring 19 aids in rotating the clamping member 12 toward its operative position.

Continuing to refer particularly to Fig. 7 of the drawings, the plunger 9i is provided with a head may twist relative to the in accommodating warped 14 and the pivot shaft 13,

9| which is slidable in a counterbore 92 in the hub 61 of the bracket y96, the stem and head of the plunger cooperating to form a shoulder which is adapted to seat on a shoulder at the junction of the bore 83 and the counterbore 92 to limit rotation of the clamping member 12 beyond its operative position. The plunger 8l of each boxengaging device 95 has pivotally connected thereto a lever 93, each of the levers 93 being pivotally connected intermediate its ends to the carriage carrying the corresponding box-engaging devices by a pin 95. Each lever 93 carries a rotatable cam follower 95 which engages a stationary cam 96 carried by the frame I0 and arranged concentrically with the shaft 21 on which the carriages 60 rotate, there being one cam 96 for each carriage. A development of one of the cams 96 is shown in Fig. 8 of the drawings and, referring thereto, each cam is provided with a cam slot which receives the cam followers 95 on the levers 93 carried by the corresponding carriage 69. As shown in Fig. 8 of the drawings, the cam slot comprises two dwells 91 and 99 connected by cam surfaces 99 and |09. As each carriage `Ei) rotates, the cam followers 95 on the levers 93 carried thereby move along the cam slot provided by the corresponding cam 9c, each cam follower maintaining the clamping member 12 of the box-engaging device 6-5 controlled thereby in its retracted position when in engagement with the dwell 91 and maintaining the clamping member in its extended position when in engagement with the dwell 98. As each cam follower 95 moves through the corresponding cam slot from the dwell 91 to the dwell 98, the cam surface 99 produces movement of the corresponding clamping member from its retracted position to its extended position, and as each cam follower moves from the dwell 99 to the dwell 91, the cam surface |99 produces movement of the corresponding clamping member from its extended position to its retracted position. Thus, the cams 99 positively control the positions of the clamping members 12 of the various box-engaging devices e5. The cams also force any misaligned boxes in the ris-ing stack into alignment gently, thus eliminating any necessity for stack straightening devices.

With the foregoing discussion of the structure of the box-engaging devices 65 in mind, the operationof the carriage means l5 will now be considered in detail. As a stack l2 of boxes is elevated by the stack-elevating means Il, the carriages 59 rotate to bring a pair of the boxengaging devices 65 into a position to engage the uppermost box in the stack, the stack-elevating means and the carriages operating in timed relationship by virtue of the mechanism described previously. As the pair of box-engaging devices reaches a position to engage the uppermost box in the stack, the cam followers 95 on the levers 93 associated with the respective box-engaging devices engage the cam surfaces 99 on the corresponding cams 96 to move the clamping members 12 of the respective devices from their inoperative positions to their operative positions. The cam surfaces 99 are so positioned that they cause the clamping members 12 to engage the box near its bottom to take advantage of the greater strength of the box at this point, which is an important feature of the invention.

Referring particularly to Figs. 2 and '7 of the drawings, it will be noted that the clamping members 12, when in their operative positions, are inclined upwardly from their respective pivot vmoved into engagement with the box 9 shafts 1-3 `so that ,as the grippingelements 14 are urged into frictional engagement with opposite surfaces of the box by the cams 96 and theV compression springs 19, the weight of the ybox tends to cause the clamping members to romovement of the clamping members 'i'toward v their operative positions is positively controlled by the cams e6, the clamping members will be so that the box will be picked up gently.

As the clamping members 12 of eachv pair of Vbox-'engaging devices engage and securely clamp the uppermost box in the stack therebetween in the foregoing manner, the box is lifted clear of the remaining boxes in the stack be.'- cause of the fact that the carriages Eare driven at a speed such that the speed of the box-engaging devices exceeds the speed of the rising stack I2, the speed ofthe box-engaging devices preferably being approximately twice that o f the rising stack in order to insure that the box will be lifted clear as soon as it is picked up by the box-engaging devices. As the carriages 60 rotate, the box is moved in a circular discharge-path toward the box-receiving station I9. At the same time, the stack-elevating means I I continues to elevate the stack of boxes sov that-the next box in the stack is moved into aposition to be picked up by the next pair of box-engaging devices 65 As the box being carried byvone of the pairs of box-engaging devices S reaches the box-receiving station l0, the corresponding cam followers encounter the cam surfaces |00 of the corresponding cams 96 and, acting through the corresponding levers e3 and plungers 8|, move the corresponding clamping .members 12. from their operative positions to their inoperative positions, thereby releasing the box. 'I'he cam surfaces H30 are so located that they cause the clamping members 'i2 to disengage the box just before the bottom of the box engages the conveyor I1 so that the contents of the box will not be jostled. have found, for example, that the cam surfaces It@ may be so positioned that the box, when disengaged by the clamping members "i2, will drop considerably less than one quarter of an inch, which is insufficient to damage even fruit which bruises easily.

Since the positions of the cam Lsurfaces 99 which actuate the box-engaging devices 65 to extend the clamping members 12 and the operation of the stack-elevating means I I are preferably so related that the clamping members of each pair of devices engage opposite surfaces of the box adjacent the bottom of the box to take advantage of the additional strength provided by the bottom, it will be apparent that the center of gravity of the box will be above the points oi contact between the surfaces of the box and the clamping members so that the box will have a tendency to overturn. Consequently, it is necessary to provide means for maintaining the box in an upright position, such a means being associated with each carriage B0 and being indicated generally by the numeral |05. As best shown in Fig. 6 of the drawings,

gradually li() each means |05 for maintaining the boxes upright includes a chain |06 which is trained around sprockets |01 carried by the respective box-engaging devices 65, an idling sprocket |98 carried by the corresponding carriage 60, and a sprocket |09. TheV sprockets |01 are xed on the hubs E1 of the brackets 66 associated with the respective Ibox-engaging devices, as best shown in Fig. 7 of the drawings. The idling sprockets |09 are rotatable relative to the respective carriages 60 on which they are mounted and the sprocket |09 associated with each carriage is rigidly connected to the frame I0 so that it remains stationary during rotation of the carriage with which it is associated. Consequently, as each carriage 69 rotates relative to the frame I0, the stationary sprocket |09, acting through the chain |66 and the sprocket |01, causes the box-engaging devices to rotate relative to the carriage in a direction opposite to the direction of rotation of the carriage relative to the frame. In order to maintain the boxes carried by the boxengaging devices t5 upright, the diameters of the vsprockets '|01 and the diameter of the xed sprocket I t9 associated with each of the carriages 6e must all be equal'so that the speed of rotation of the box-engaging devices with respect to the carriages on which they are mounted will be equal to the speed of rotation of the carriages with respect to the frame I0 in order to maintain constant the orientation of the box-engaging devices with respect to the frame. Thus, the boxes are maintained upright as they are moved from the stack I2 to the box-receiving station |6.

lt will be noted that although the foregoing means |65 for Amaintaining the boxes upright would not be essential if the cam surfaces ls were so positioned that the clamping members i2 engage the boxes above the centers of gravity thereof, theboxes would then be free to swing andI damage to the contents thereof might result. The mechanism previously described, in addition to maintaining the boxes in upright positions, prevents any swinging of the boxes, which is an important feature of the invention.

As the boxes transported by the carriage means I5 reach the box-receiving station it, they are removed therefrom by the conveyors ii' and i9, as previously indicated. The conveyor i1 may, for example, include a pair of chains IIS each of which is trained over sprockets iid and H5, the sprockets IIlt being fixed on the shaft 21 and the sprockets I|5 being carried by a shaft IIS journalled in suitable bearings carried by the frame I0. Since the shaft 21 is driven by the chain 32 in the manner previously described, it will drive the conveyor I1, as will be apparent.

As best shown in Figs. 1 and 3 of the drawings, the conveyor I3 comprises a ramp |223 which is inclined downwardly away from and forms a continuation of the conveyor |1, the ramp car- Y rying a plurality of rollers |2| over which the boxes move. The means le for rotating each box about a substantially vertical axis as it e moves from the conveyor Ii onto the conveyor i8 inclu-:ies a roller |22 which is adapted to engage the bottom of the box at one end thereof to remove the weight of one end of the box from the corresponding chain H3, the roller being rotatable about an axis inclined at an angle of approximately 45I with respect to the direction of movement oi the box on the conveyors I1 and i8. The rotating means I9 also includes a stop, exemplied as a guard rail |23, which serves to restrain one end of the box so that the opposite end thereof is moved onto the conveyor I8 by one of the chains |I3 of the conveyor I1, the inclined roller |22 serving to permit free rotation of the box. Thus, each box is moved sidewise by the conveyor until one end of the box rests on the inclined roller |22 and engages the guard rail |23, whereupon the other end of the box is moved forwardly to rotate the box into a position such that it moves endwise along the conveyor I8, which is an important feature of the invention.

I have found that my box-unstacking apparatus is capable of handling boxes in a very gentle manner because of the fact that they are picked up gently by the box-engaging devices 65, and because of the fact that the boxes are not released by the devices 65 until they have been placed on or substantially on the conveyor The mechanism for maintaining the boxes upright as they are removed from the stack and transported to the box-receiving station I6 also eliminates any possibility of damage to the contents of the boxes which might result if the boxes were permitted to swing freely from the carriages 60.

In addition to being capable of handling boxes with a minimum of jolting, the apparatus is also capable of stacking boxes at a high rate of speed. For example, I have found that a machine constructed substantially in accordance with the foregoing disclosure is capable of unstacking boxes at a rate of ninety per minute'.

Although I have described an exemplary embodiment of my invention herein for purposes of illustration, it will be understood that I do not desire to be limited thereto since various changes, modications and substitutions may be incorporated in the embodiment disclosed without necessarily departing from the spirit of the invention.

Consequently, I hereby reserve the right to all such changes, modifications and substitutions as properly come Within the scope of my invention as set forth in the appended claims.

I claim as my invention:

1. In a box-handling apparatus, the combina tion of: a pair of supporting members; a pair of clamping members adapted to engage opposite surfaces of a box; means pivotally connecting said clamping members to said supporting members, respectively, said pivotal connecting means providing substantially parallel axes of rotation for said clamping members to permit rotation of said clamping members inwardly toward each other into engagement with' opposite surfaces of a box and to permit rotation of said clamping members outwardly away from each other to release the box, said pivotal connecting means further providing lost-motion connections between said clamping members and said supporting members to permit shifting of said clamping members relative to said supporting members to accommodate irregular box surfaces; means for moving said supporting members and the re spective clamping members along parallel paths; and means for moving said clamping members inwardly toward each other and outwardly away from each other at predetermined points on said paths.

ReferencesCited in the file of this patent UNITED STATES PATENTS Number Name Date 115,406l Woolf May 30, 1871 276,008 Dickey Apr. 17, 1883 791,601 Andrus June 6, 1905 1,510,096 Miller Sept. 30, 1924.

1,676,957 Leaver July 10, 1928 1,785,374 Bronson Dec. 16, 1930 1,969,994 Stevenson Aug. 14, 1934 .2,362,517 Woodberry Nov. 14, 1944 2,424,252 Orlando July 22, 1947 2,590,225 Bashore Mar. 25, 1952 FOREIGN PATENTS Number Country Date 283,754 Germany Apr. 23, 1915 

